| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.apex.malhar.lib.transform; |
| |
| import java.lang.reflect.Field; |
| import java.util.HashMap; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| import javax.validation.constraints.NotNull; |
| |
| import org.apache.apex.malhar.lib.expression.Expression; |
| import org.apache.apex.malhar.lib.util.PojoUtils; |
| import org.apache.commons.lang3.ClassUtils; |
| |
| import com.datatorrent.api.Context; |
| import com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.Operator; |
| import com.datatorrent.api.annotation.InputPortFieldAnnotation; |
| import com.datatorrent.api.annotation.OutputPortFieldAnnotation; |
| import com.datatorrent.common.util.BaseOperator; |
| |
| /** |
| * This operator can transform given POJO using provided expressions and |
| * return a final POJO as a return of transformation process. |
| * |
| * Following are the mandatory fields that needs to be set for TransformOperator to work: |
| * <ul> |
| * <li><b>expressionMap</b> : Set how the transformation should happen</li> |
| * <li><b>inputPort.attr.TUPLE_CLASS</b>: Set class type at input port</li> |
| * <li><b>outputPort.attr.TUPLE_CLASS</b> : Set class type at output port</li> |
| * </ul> |
| * |
| * The operator uses interaction via {@link Expression} and {@link PojoUtils} to transform given POJO. |
| * |
| * @since 3.4.0 |
| */ |
| public class TransformOperator extends BaseOperator implements Operator.ActivationListener |
| { |
| @NotNull |
| private Map<String, String> expressionMap = new HashMap<>(); |
| protected List<String> expressionFunctions = new LinkedList<>(); |
| private boolean copyMatchingFields = true; |
| |
| private transient Map<PojoUtils.Setter, Expression> transformationMap = new HashMap<>(); |
| protected Class<?> inputClass; |
| protected Class<?> outputClass; |
| |
| public TransformOperator() |
| { |
| expressionFunctions.add("java.lang.Math.*"); |
| expressionFunctions.add("org.apache.commons.lang3.StringUtils.*"); |
| expressionFunctions.add("org.apache.commons.lang3.StringEscapeUtils.*"); |
| expressionFunctions.add("org.apache.commons.lang3.time.DurationFormatUtils.*"); |
| expressionFunctions.add("org.apache.commons.lang3.time.DateFormatUtils.*"); |
| } |
| |
| @InputPortFieldAnnotation(schemaRequired = true) |
| public final transient DefaultInputPort<Object> input = new DefaultInputPort<Object>() |
| { |
| @Override |
| public void setup(Context.PortContext context) |
| { |
| inputClass = context.getValue(Context.PortContext.TUPLE_CLASS); |
| } |
| |
| @Override |
| public void process(Object o) |
| { |
| processTuple(o); |
| } |
| }; |
| |
| @OutputPortFieldAnnotation(schemaRequired = true) |
| public final transient DefaultOutputPort<Object> output = new DefaultOutputPort<Object>() |
| { |
| @Override |
| public void setup(Context.PortContext context) |
| { |
| outputClass = context.getValue(Context.PortContext.TUPLE_CLASS); |
| } |
| }; |
| |
| protected void processTuple(Object in) |
| { |
| if (!inputClass.isAssignableFrom(in.getClass())) { |
| throw new RuntimeException( |
| "Unexpected tuple received. Received class: " + in.getClass() + ". Expected class: " + inputClass.getClass()); |
| } |
| |
| Object out; |
| try { |
| out = outputClass.newInstance(); |
| } catch (InstantiationException | IllegalAccessException e) { |
| throw new RuntimeException("Failed to create new object", e); |
| } |
| |
| for (Map.Entry<PojoUtils.Setter, Expression> entry : transformationMap.entrySet()) { |
| PojoUtils.Setter set = entry.getKey(); |
| Expression expr = entry.getValue(); |
| set.set(out, expr.execute(in)); |
| } |
| |
| output.emit(out); |
| } |
| |
| @Override |
| public void activate(Context context) |
| { |
| if (copyMatchingFields) { |
| Field[] declaredFields = outputClass.getDeclaredFields(); |
| for (Field outputField : declaredFields) { |
| String outputFieldName = outputField.getName(); |
| if (!expressionMap.containsKey(outputFieldName)) { |
| try { |
| Field inputField = inputClass.getDeclaredField(outputFieldName); |
| if (inputField.getType() == outputField.getType()) { |
| expressionMap.put(outputFieldName, inputField.getName()); |
| } |
| } catch (NoSuchFieldException e) { |
| continue; |
| } |
| } |
| } |
| } |
| |
| for (Map.Entry<String, String> entry : expressionMap.entrySet()) { |
| String field = entry.getKey(); |
| String expr = entry.getValue(); |
| |
| // Generate output setter |
| Field f; |
| try { |
| f = outputClass.getDeclaredField(field); |
| } catch (NoSuchFieldException e) { |
| throw new RuntimeException("Failed to get output field info", e); |
| } |
| |
| Class c = ClassUtils.primitiveToWrapper(f.getType()); |
| PojoUtils.Setter setter = PojoUtils.createSetter(outputClass, field, c); |
| |
| // Generate evaluated expression |
| |
| Expression expression = PojoUtils |
| .createExpression(inputClass, expr, c, expressionFunctions.toArray(new String[expressionFunctions.size()])); |
| |
| transformationMap.put(setter, expression); |
| } |
| } |
| |
| @Override |
| public void deactivate() |
| { |
| } |
| |
| /** |
| * Returns expression map which defines outputFieldName => Expression mapping. |
| * |
| * @return Map of outputFieldName => Expression |
| */ |
| public Map<String, String> getExpressionMap() |
| { |
| return expressionMap; |
| } |
| |
| /** |
| * Set expression map (outputFieldName => Expression) which defines how output POJO should be generated. |
| * This is a mandatory property. |
| * @param expressionMap Map of String => String defining expression for output field. |
| * |
| * @description $(key) Output field for which expression should be evaluated |
| * @description $(value) Expression to be evaluated for output field. |
| * @useSchema $(key) output.fields[].name |
| */ |
| public void setExpressionMap(Map<String, String> expressionMap) |
| { |
| this.expressionMap = expressionMap; |
| } |
| |
| /** |
| * Returns the list of expression function which would be made available to expression to use. |
| * |
| * @return List of function that are available in expression. |
| */ |
| public List<String> getExpressionFunctions() |
| { |
| return expressionFunctions; |
| } |
| |
| /** |
| * Set list of import classes/method should should be made statically available to expression to use. |
| * For ex. org.apache.apex.test1.Test would mean that "Test" method will be available in the expression to be |
| * used directly. |
| * This is an optional property. See constructor to see defaults that are included. |
| * |
| * @param expressionFunctions List of qualified class/method that needs to be imported to expression. |
| */ |
| public void setExpressionFunctions(List<String> expressionFunctions) |
| { |
| this.expressionFunctions = expressionFunctions; |
| } |
| |
| /** |
| * Tells whether the matching (by name and by type) fields between input and output should be copied as is. |
| * |
| * @return Tells whether the matching (by name and by type) fields between input and output should be copied as is. |
| */ |
| public boolean isCopyMatchingFields() |
| { |
| return copyMatchingFields; |
| } |
| |
| /** |
| * Set whether the matching (by name and by type) fields between input and output should be copied as is. |
| * This is an optional property, default is true. |
| * |
| * @param copyMatchingFields true/false |
| */ |
| public void setCopyMatchingFields(boolean copyMatchingFields) |
| { |
| this.copyMatchingFields = copyMatchingFields; |
| } |
| } |